Spray gun to simultaneously spray two mediums from one nozzle



Nov. l, 1969 w z PP 2,958,471

SPRAY GUN TO SIMULTANEOUSLY SPRAY TWO MEDIUMS FROM ONE NOZZLE Filed May 27. 1958,

SPRAY GUN TO SMULTANEOUSLY SPRAY TWO MEDIUMS FROM ONE NOZZLE Berndt W. Zippel, Braugasse 6, Waldkappel, near Eschwege, Germany Filed May 27, 1958, Ser. No. 738,222

6 Claims. (Cl. 239-414) The present invention relates to a spray gun which enables a simultaneous discharge of two mediums from one nozzle. With particular advantage, the spray gun, in accordance with the present invention, is used to spray polyester varnish together with a hardening or catalytic agent which should be blended at the moment of discharge only.

In .one of the known embodiments of a spray gun, one of the mediums is fed to the nozzle directly from a chamber, and the other medium through a pipe which serves as a nozzle needle and extends axially through the chamber, the pipe being axially displaceable by the lever controlling the air supply. This pipe extends from the nozzle body to the handle where it is slideably journalled. A spring, accommodated in the handle and acting on the pipe, tends to force the pipe into a position to close the nozzle through which the first medium is discharged. Feed of the second medium to the pipe is through a connecting piece at the end of the pipe projecting from the handle. At the opening of this connecting piece into the pipe a manually adjustable nozzle needle is provided which allows for a variation of the amount of the second medium until the connecting piece is completely closed.

Variations in the supply and a manual shut-off of the second medium is not desirable because it is difiicult or not at all possible to control this action, during the operation. The nozzle for the discharge of the first medium will be closed by the hollow nozzle needle when releasing the operating lever. The second medium, however, will continue to leave the hollow nozzle needle for a more or less long period. This subsequent discharge of the second medium alone may cause undesired stains on the sprayed surface. The proportion of the hardening or catalytic agent admixed to the polyester varnish must be constant. In the known apparatus, however, the proportion varies according to the operating lever being pressed more or less and the nozzle being opened more or less. In any case, when the nozzle is only slightly opened, a bigger amount of the second medium will be discharged than is necessary to produce the correct mixture. A constant control by means of manual adjustment of the nozzle needle which controls the supply of the second medium is not possible.

It is, therefore, one object of the present invention to eliminate the deficiency of known structures by providing a solid nozzle needle which extends throughout a hollow nozzle needle for feeding the second medium, and the solid needle is connected with the operating lever so that when pressing the operating lever, it is displaced together with and also relative to the hollow nozzle needle. The channel to feed the second medium to the hollow nozzle needle is arranged close to the nozzle body, and the bore of the needle is reduced at the rear end so that in this part the solid nozzle needle is sealingly guided. At the rear end the solid needle projects beyond the hollow needle and is indirectly controlled by the operating lever. To connect the solid needle with the operating lever, 21

2,958,471 (:6 Patented Nov. 1, 196i) second lever is arranged on the handle parallel to the operating lever and pivots at the opposite end as compared to the operating lever. An abutment on the operating lever bears against the second lever. The abutment is axially adjustable so that the leverage of both levers can be varied. According to the leverage the relative motion of the solid needle with respect to the hollow needle is diiferent. Another adjustment is also possible in that the operating lever is pivoted on the handle at different distances from the common axis of the hollow and the solid nozzle needle. 7

With this and other objects in view, which will become: apparent in the following detailed description, the present invention will be clearly understood in connection with. the accompanying drawing, in which the only figure isan axial section of the spray gun.

Referring now to the drawing, the body 1 of the spray gun comprises a handle 10 and an arm 1b with a nozzle body 18 removably mounted on its end and being held by a nut 19. Within the handle 1a, a channel 10 to supply compressed air for the operation of the spray gun, and an air shut-off valve 2. are provided. The air shut-off valve 2 is in communication with an air distributor 26 on the nozzle body 18 by means of a pipe 20a. The air distribution chamber 20 is formed by an annular hollow space, which is disposed between the tapered-down nozzle 3 of the nozzle body 18 and a cap member 21 has a central bore and is shaped complementary to the tapered-down nozzle 3 of the nozzle body 18. The nozzle body 18 defines a chamber 18a, into which the paint, in the present case preferably polyester varnish, is fed through a connecting piece 7. The latter projects through a bore of the arm 1b of the body 1 and serves jointly with the nut 19, screwed thereon, for securing the nozzle body 18 to the arm lb. To close the tapered-down nozzle 3 in the nozzle body 18 feeding paint, a hollow nozzle needle 4 extends axially through the paint chamber in the nozzle body 18. The needle is axially displaceable, and in its rest position its pointed end 4a is forced into a tapered seat 5 in the tapereddown paint nozzle 3 by means of a spring 15. Inside of and coaxial with the hollow needle 4 a solid nozzle needle 6 is provided which extends throughout the hollow nozzle needle 4 and which at its rear end projects beyond the latter one. The bore 4b of the hollow needle i is wider in the front part than the outer diameter 6' of the solid needle 6, while in the rear part it is of the same dimension as the diameter 6 of the solid needle 6, so that in this part the solid needle 6 is sealingly guided in the hollow needle 4. Outside the nozzle body 18, as seen in the direction towards the handle 1a, where the reduced inner diameter begins, a connecting piece 8 is provided on the hollow needle '4 for the feed of the second spraying medium which, in the present case, would be a hardening agent or a catalytic agent for the polyester varnish.

The rear end of hollow nozzle needle 4 is guided in a sleeve 12 which is slideable in the body 1 of the spray gun. The rear end 6a of the solid needle 6 projecting beyond the end of the hollow needle 4 is fixed to the bottom of the sleeve 12. The spring 15 is disposed inside the sleeve 12 at the rear end 6a of the solid needle 6 projecting beyond the hollow needle 4. The spring 15 rests against the bottom of the sleeve 12 and against the end 17 of the hollow needle 4. Thus, the spring 15 tends to force the hollow needle 4 towards the nozzle body 18, and the tapered front end 4a of the hollow nozzle needle 4 into the tapered seat 5 of the tapereddown paint nozzle 3 of the nozzle body 18 to close the latter. On the other hand, a spring 16 which is accommodated in the handle 1a of the spray gun, acts on the sleeve 12, the spring 16 pressing the sleeve 12 and the 3 solid nozzle needle 6 which is fixedly connected with the sleeve 12, towards the nozzle body 18. Consequently, the mouth 4' of the hollow needle 4 is also closed by means of the end of the solid needle 6. The tapered sealing area at the mouth 4 of the hollow needle 4 and the solid needle 6 is comparatively large.

' A trigger 9 is pivoted on a projection 1d of the body 1 of the spray gun, above the hollow needle 4 and forms a'fork to enclose the hollow needle 4. The trigger 9 bears against adjusting nuts 11 provided on the hollow needle 4 between the trigger 9 and the handle 1a of the spray gun. By operating the trigger 9, the outer needle 4 is displaced, against the action of the spring 15 towards the handle 1a, and the tapered-down paint nozzle 3 is opened.

Arranged parallel to the trigger 9, a second lever is pivoted at its lower end on a projection 1e of the handle 1a of the spray gun between the trigger 9 and the handle 1a of the spray gun. Thus, the pivot point of the lever 10 is below the common axis of the hollow needle 4 and the solid needle 6. Its free end 10a is forkshaped and rests against the end of the slideable sleeve 12 which. faces the nozzle body 18. An abutment 14 provided on the trigger 9 below the hollow needle 4 rests against the upper end of the lever 10. By operating the trigger 9, the lever 10 is also actuated. During this movement of the lever 10, the sleeve 12 and the needle 6 which is fastened to the latter, are forced back against the action of the spring 16. When pulling the trigger 9, the hollow needle 4 and the solid needle 6 are displaced together. The abutment 14 is arranged on the trigger 9 so that the solid needle 6 carries out at the same time a relative motion with respect to the hollow needle 4, and the mouth of the hollow needle 4 is opened.

The abutment 14 is axially adjustable on the trigger 9 so that the leverage of the trigger 9 and the lever 10 is variable. The more the abutment 14 is moved away from the pivot point of the trigger 9, the greater is the relative motion of the solid needle 6 with respect to the hollow needle 4. In this way it is possible to vary the proportion of the medium discharged from the hollow needle 4, Le. the hardening or catalytic agent, and the amount of the medium discharged through the tapereddown paint nozzle 3, i.e. the polyester varnish, to a wide extent.

Preferably, several alternative pivot points 13, 13a, 13b are provided for the trigger 9 on the handle 1:: of the spray gun at different distances from and above the common axis of both nozzle needles 4 and 6. The effective length of the lever 10 acting on the hollow needle 4 is different according to the pivot point used for the trigger 9. When varying the position of the abutment 14 on the trigger 9, the lever action is infinitely variable, and when varying the pivot point of the trigger 9, the leverage is varied step by step. Preferably, both adjusting means are provided on the spray gun to enable a rough and a time adjustment.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. A spray gun for spraying two media from a single nozzle, comprising a handle and a nozzle body, the latter defining a chamber adapted to discharge therefrom one j i r of said two media, a hollow nozzle needle axially displaceably mounted in and projecting from said handle through said chamber, said hollow nozzle needle being adapted to discharge another of said two media, an air shut-01f valve disposed in said handle, and an air distributor operatively connected with said valve and secured to said nozzle body, a solid nozzle needle axially movable within said hollow nozzle needle and extending rearwardly beyond the rear end of said hollow nozzle needle, a trigger-member controlling the axial displacement of said hollow nozzle needle, and a lever operatively connected with said solid nozzle needle, and means causing operation of said lever upon operation of said trigger member, so that upon operation of said trigger member said solid nozzle needle is axially displaced simultaneously with and relative to said hollow nozzle needle.

2. The spray gun, as set forth in claim 1, which includes a conduit feeding one of said media into said hollow nozzle needle, said conduit being disposed close to said nozzle body, and said solid nozzle needle tightly fitting into the rear portion of said hollow nozzle needle.

3. The spray gun, as set forth in claim 1, wherein said handle has a pivot for pivotal connection of said trigger member with said handle and said lever is disposed on said handle parallel to said trigger member and pivoted at the end opposite to that of said pivot of said trigger member, and an abutment member secured to said trigger member, said abutment member bearing against said lever, and the latter controlling the displacement of said solid nozzle needle.

4. The spray gun, as set forth in claim 3, wherein said abutment member is adjustable along the longitudinal axis of said trigger member.

5. The spray gun, as set forth in claim 1, whereinsaid trigger member has a plurality of pivot receiving bores axially spaced apart from each other to mount said trigger member in said handle and to vary the effective length of said trigger member.

6. The spray gun, as set forth in claim 1, which includes a sleeve having a bottom and being displaceable in said handle, a first spring disposed between said bottom of said sleeve and said hollow nozzle needle, and a second spring disposed between an annular face of said handle and a shoulder of said sleeve to force said sleeve towards said nozzle body, and said solid nozzle needle being fixedly connected to said bottom of said sleeve and the rear end of said hollow nozzle needle sliding in said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,662,042 Birkenmaier Mar. 6, 1928 1,751,608 Tittemore et a1 Mar. 25, 1930 1,939,607 Krautzberger Dec. 12, 1933 1,958,730 Tracy May 15, 1934 1,987,248 Seizer Jan. 8, 1935 2,497,625 Norwick Feb. 14, 1950 2,553,848 Dalrymple May 22, 1951 2,619,386 Dalrymple Nov. 25, 1952 2,904,343 Friedell Aug. 27, 1957 2,808,294 Tamminga Oct. 1, 1957 FOREIGN PATENTS 153,075 Austria Apr. 11, 1938 

